CN104352225B

CN104352225B - System and method for monitoring cardiorespiratory parameters

Info

Publication number: CN104352225B
Application number: CN201410482368.6A
Authority: CN
Inventors: P·德沙扎尔; C·汉利; C·赫尼根
Original assignee: Biancamed Ltd
Current assignee: Resmed Sensor Technologies Ltd
Priority date: 2006-11-01
Filing date: 2007-10-31
Publication date: 2019-10-25
Anticipated expiration: 2027-10-31
Also published as: EP2078270A2; EP2078270B1; CA2668400A1; JP5628520B2; CN101689219A; US20100179438A1; WO2008057883A3; CN104352224A; AU2007317469B2; US8834364B2; EP3967219A1; CA2668400C; JP2010508128A; EP2469436B1; EP2469436A2; WO2008057883A2; JP2015027550A; US20140350361A1; JP6386327B2; CN104352224B

Abstract

It discloses for monitoring movement, breathing, heart rate and with come the equipment, system and method that export and show the measurement of cardiorespiratory performance by the signal.Signal by being applied in a non contact fashion, the processing of the original signal typically obtained using radio frequency sensor and obtain.Describe processes composition from heart and respiratory components.Heart rate can be determined by using frequency spectrum or Time Domain Processing.Spectrum analysis can be used to be calculated for respiratory rate.Describe the processing using this system export heart rate, respiratory sinus arrhythmia or ventilation threshold parameter.Sensor, processor and display may be incorporated into single device, and other sensors are can integrate, such as position locator, the single device is wearable in body-building physically or close to body to be fixed, or is selectively placed on the fixing piece of the health and fitness facilities apart from body certain distance.

Description

System and method for monitoring cardiorespiratory parameters

The application is entitled " system and method for monitoring cardiorespiratory parameters " submitted on June 17th, 2009 The divisional application of Chinese patent application 200780046662.0.

The cross reference of related application

This application claims 60/863, No. 862 priority of the U.S. Provisional Application No. submitted on November 1st, 2006, should The full content of provisional application is incorporated herein by reference.

Technical field

The present invention relates in a manner of useful convenience for example in the evaluation of cardiovascular fitness and activation flag and low cost Movement, breathing and the heart rate of living body such as people are monitored, and more specifically to a kind of for can easily be understood that Mode obtains, handles and shows the equipment, system and method for corresponding information.In this application, with reference to it is measurable movement, exhale It inhales and the system of heart rate is as cardiopulmonary monitoring device or system.

Background technique

The monitoring of heart rate and breathing is conducive to evaluate the performance of cardiorespiratory system.For example, the heart when the general level of the health of adjuster The measurement of rate is useful, establishes the normal heart rate range of physiology well because of the activity level for having had response different Criterion.The measurement of heart rate is widely used in healthy drill program.It fights for example, heart rate is maintained at per minute 100 with 120 times Movement between dynamic (bpm) may be useful for weight-reducing and endurance training, and athletics may want to bear Heart rate level is promoted into the activity to 160-180bpm.Further, it has been determined that can reliably adjust for age and gender The level of section enables and plans that interested individual quantitatively monitors their progress to constructed cardiovascular health.Cause This, it is desired to be able to heart rate is measured under circumstances.However, reliable heart rate measurement proposes certain skill under moving condition Art challenge.When running or cycling, motion artifact can destroy heart rate measurement.When swimming, to the conduction due to water The electric measurement of characteristic, heart rate may be difficult.

In addition to heart rate, respiratory rate, depth of respiration and breathing pattern are also the useful instruction of the integrality of cardiorespiratory system Device.Clear view is to respiratory rate increases in response to movement, but increases (or reducing during exercise recovery period) Rate is the mark of overall cardiorespiratory health.For the people with damaged cardiorespiratory status, such as may undergo dyspneic People, the respiratory rate of raising are the useful marks of state.

Heart rate and the separating and measuring of breathing be valuable but useful measurement can also from provide all marks these It is exported in the combination of measurement.For instance, it is known that the physiological Mechanism that breathing passes through referred to as respiratory sinus arrhythmia (RSA) Directly adjust heart rate, wherein heart accelerates in intake period, and slows down during expiration.RSA is especially aobvious in young man It writes, and tend to vary with the age to tend to decline.Typically, however, the RSA of high level is associated with health, and will be responsive to transport Dynamic and changes in diet and change (see, for example, " the Respiratory sinus of Ronald E.DE Meersman Arrhythmia alteration following training in endurance athletes (is instructed in endurance athletes Respiratory sinus arrhythmia variation after white silk) ", it is published in European Journal of Applied In Physiology, vol.64, no.5, in September, 1992, the 434-436 pages).However, in order to quantify RSA, heart rate and breathing Measurement is desired simultaneously.

Other useful parameters of cardiovascular fitness are anaerobic threshold (AT) and ventilation threshold (VT).Anaerobic threshold is cardiorespiratory system The point of enough oxygen is not provided to muscle, because the energy demand of muscle is fully met by aerobic metabolism process.Therefore, body exists Using its glycogen deposit to maintain muscle to export in anaerobic metabolic process.In this point, people has reached their maximum oxygen intake, And it will become in a short time too tired and their activity level cannot be maintained (maximum oxygen intake is referred to as VO_{2, max}).In order to Accurately measure AT, it is desirable that special laboratory equipment and blood sampling, therefore although this is used as " gold standard ", it is right In by interested personal generally using being unpractical to health.Ventilation threshold is physiologically related to anaerobic threshold.It is Nonlinear point is become for the minute ventilation response (liter/min of breathing air) of exercise intensity, and by the big of respiratory rate Amplitude increases and marks.In terms of oxygen healthy viewpoint, it has been shown that anaerobic threshold and ventilation threshold are very relevant.Due to The target of many fitness programs is to increase AT, so it is useful for VT capable of being used as reliable surrogate markers.Cardiorespiratory monitor It can be used for the combination by using respiratory rate and heart rate and estimate VT.This will provide practicability for the user of monitor, because They can track the trend of their VT on long period (for example, in the process of health training planning).

In clinical setting, the reliable markers with cardiovascular fitness are also useful.For example, the people with heart failure has There is very high movement intolerance.Some objects with heart failure are the candidates of heart transplant, but to a certain degree can be diligently Dirty shortage, doctor must sort by the sequence of the seriousness of patient disease to patient.Equally, in this case, VT Measurement can be useful in terms of the holistic health of evaluation patient.D.Ramos-Barb ó n, D.Fitchett, " the Maximal Exercise Testing for the of W.J.Gibbons, D.A.Latter and R.D.Levy selection of Heart Transplantation Candidates-Limitation of Peak Oxygen Consumption (for selecting largest motion test-peak value oxygen consumption limit of heart transplant candidate) " Chest.1999；The challenge discussion that cardiopulmonary mark is evaluated to evaluate heart transplant candidate is provided in 115:410-417.

Heart rate measurement for the purpose of evaluation cardiovascular fitness has numerous species technology.Surface lead electrocardiograms (ECG) It is the approach for the pin-point accuracy for capturing cardiac electrical activity and therefore capturing heart rate.However, they require object by gelled electrodes It is placed on chest region, and also carries or wear relevant electron process and/or recording device.So generally, ECG measurement is complete It is limited to clinical application.

Have been incorporated into the more easily technology for ecg measurement, and the heart being now widely used in commercially available now In rate health monitor, these technologies victim signal quality in order to facilitate property.These technologies, which use to be embedded in, is placed to skin Electrode in neighbouring conductive fabric.Typically, fabric is formed in a part for the chest strap worn at chest level around chest.Due to The electric conductivity of textile material depends on water content, so these sensors exert oneself to move in people and skin is moistened by sweat When, works preferably (selectively the coatable some conducting resinls of user are to guarantee good electric measurement).The shortcomings that system It is, it is desirable that people wears chest strap and signal quality reduces when the skin of people is not wet.

It is the pulse blood oxygen measurement using pulse oximetry methods for evaluating another technology of heart rate during movement Method measures the variation of the reflection/transmission light across blood vessel.It can produce feature photoplethysmographic figure, in this feature photoelectricity volume In pulse wave figure, each heart contraction is visible as different pulse.However, being used to measure the pulse blood oxygen measurement of heart rate Method is limited by motion artifact and bad perfusion characteristics.The power requirement of the light emitting diode used in oximeter is also likely to be this The limiting factor of the battery life of kind device.

Respiratory effort and respiratory rate can also measure in many ways.Commonsense method for measuring respiratory effort uses electricity Feel plethysmography, in the inductance plethysmography, people wears close-fitting elastic band around their chest, when people sucks With the inductance variation of elastic band when exhalation.The limitation of this method is that people must wear band, and through leading from the viewpoint of the convenience Line remains connected on associated electrical recording device.Optional system for measuring respiratory effort is using impedance spirography Method measures the impedance variations of chest in the impedance pneumography.The limitation of the technology is that it requires electrode to be connected to body On, and there is the active electrical component for needing to be carried by object.

For cardiorespiratory fitness assessment, it is useful for measuring all-around exercises, because this is the whole of daily routines and exercise intensity Body instruction.It is using accelerometer for measuring the movable most common technology of free living, which can measure acceleration.When by When people carries, this device can provide the total duration of the movement of people and the useful instruction of intensity.This device is commercially It is sold often as pedometer (step-by-step counter).The limitation of the technology, which will ask for help, carries the device and for that will measure Acceleration is converted into the limitation on the algorithm of activity pattern.

So what is desired is that, it is a kind of for measure heart rate, respiratory rate and effort and movement method, system and Equipment, this method, system and equipment overcome the various limitations of conventional means.

Summary of the invention

The present invention is provided for each embodiments and aspect of monitor heart rate, breathing and the equipment, system and method for movement. In one embodiment, sensor unit can be worn (for walking use), or be placed on fixed position (for example, making For the part of exercycle).Sensor is communicated with processor and display, and in one aspect, sensor, processor and aobvious Show that device can physically be implemented in same unit.Processor can be used to extract about heart rate, breathing and the information of movement With more advanced information (for example, Current heart rate relative to former period).Display is configured to provide a user feedback, such as Show Current heart rate or respiratory rate.Also sound (for example, sound of each heartbeat for detecting) can be used to provide instead Feedback.In one aspect, holonomic system may include one or more motion sensors (for detect general body kinematics, breathing, And heart rate)；Processing capacity (the export signal directly related with cardiomotility, breathing and movement, and therefore export and such as exhale Inhale the parameters such as rate, heart rate and movement)；Display capabilities (provide visible feedback)；Hearing ability (sound feedback is provided, such as Tone of its frequency with respiratory variations or the sound about the heartbeat detected every time)；And/or the data that will acquire are emitted to The communication capacity (wired or wireless) of isolated unit.The unit of this separation can be configured to execute above-mentioned processing, show Show and auditory function.

In one or more embodiments, a kind of to be used to measure, analyze and show breathing, cardiomotility and body fortune Dynamic system includes: one or more sensors, is configured to receive reflected radio (RF) signal from living body, wherein RF signal Including pulsed RF signal.Configuration processor is for analyzing the reflection signal with the measurement result for the physiological activity for determining living body.It is aobvious Show that device is arranged to the user for choosing information to be supplied to system relevant to the physiological activity.On the other hand, one kind is used to The system of measurement, analysis and display breathing, cardiomotility and body kinematics includes: one or more sensors, is configured to connect Reflected radio (RF) signal from living body is received, wherein RF signal includes single RF frequency.On the other hand, a kind of to be used to survey The system of amount, analysis and display breathing, cardiomotility and body kinematics includes: one or more sensors, is configured to receive Reflected radio (RF) signal from living body；And processor, it is configured to analyze the physiological activity of the reflection signal to determine living body Measurement.The system can also include transmitter, which generates the reflected radio-frequency signal from living body, and by this system The power stage of sending is for being safe for people's continuous use.The physiological activity of monitoring with may include breathing, cardiomotility and body The movement of the big movement (such as arms swing) of body is corresponding.

In another embodiment, a kind of side for measuring, analyzing and showing breathing, cardiomotility and body kinematics Method includes: the radiofrequency signal for receiving and reflecting from human body；The reflection signal is analyzed to generate breathing, cardiomotility and the body with human body Body moves relevant measurement result；And the user that information will be chosen to be supplied to system.

Detailed description of the invention

It is now described with reference to the drawings the embodiment of the present invention, in the accompanying drawings:

Fig. 1 is how the system for indicating embodiment can be used in the schematic diagram in movement and movable evaluation；Fig. 1 (a) is shown The embodiment of system as upper arm cuff；Fig. 1 (b) is shown is as the clipping arrangement that may be affixed in shirt pocket System；Fig. 1 (c) shows the example for the device worn as the pendant hung on neck；Fig. 1 (d) is indicated in treadmill body-building system Cardiorespiratory monitor in system；Fig. 1 (e) gives the example of the cardiorespiratory monitor of insertion exercycle；And Fig. 1 (f) is shown As the device of wristwatch-like device when swimming.

Fig. 2 provides the schematic illustrations of the sensor element of one embodiment.

Fig. 3 provides the representative raw sensor obtained when sensor is close to body surface (for example, in 5cm) Signal.

The upper curve of Fig. 4 shows the time course of the photoplethysmographic signal obtained from adult body, wherein often Secondary heartbeat is associated with different pattern (distinctive pattern), and the lower curve of Fig. 4 is indicated in several meters of distances The signal that place obtains simultaneously from same target, shows breathing and the heart signal of separation.

Fig. 5 indicates application for indicating using T/F, and such as short time discrete Fourier transform and wave crest detect algorithm to comment The result of the technology of fixed and visualization breathing and heart information.

Fig. 6 is provided when multiple radio frequencies (RF) block similar with those of description radio frequency (RF) block in Fig. 2 is for wireless The system schematic when transmitting and reception of electric wave.

Fig. 7 indicates the schematic diagram of the display for system.

Fig. 8 shows the schematic diagram how system calculates parameter relevant to ventilation threshold.

Specific embodiment

Fig. 1 is the schematic diagram for indicating various environment, and in these environment, this system can be used in movement and movable evaluation In.Firstly, the present apparatus can be used in walking application, (wherein people can freely be moved, because they are just adorning oneself with cardiopulmonary monitoring Device).Fig. 1 (A) shows the embodiment of the system as upper arm cuff.Fig. 1 (B) is shown as can be attached in shirt pocket Clipping arrangement system.Fig. 1 (C) shows the example for the device worn as the pendant hung on neck, and Fig. 1 (D) is indicated Cardiorespiratory monitor in treadmill body-building system, Fig. 1 (E) give the example of the cardiorespiratory monitor in insertion exercycle, with And Fig. 1 (F) shows the device in swimming as wristwatch-like device.The device may also be configured to and other known fitness equipment Tool is used together.

Fig. 2 provides schematically illustrating for exemplary sensor element.Sensor element is detected using radio frequency and is handled to mention Take body kinematics associated with breathing and heart rate.Body kinematics associated with breathing are easy to observe, because breathing is drawn Play the movement of chest and abdomen.Movement associated with cardiomotility is less obvious, but physiologist using term, " retouch by heart impact The pressure wave that note figure " Lai Zhidai is shown due to heart contraction and at skin surface.The movement of this very little can be by sensible motion Sensor detection.

This system penetrates radiofrequency signal to human hair.Reflection signal is then received, amplifies and a part of phase with original signal Mixing, and the output of this frequency mixer and then be low pass filtering.Therefore the output of this frequency mixer can be used as penetrating from reflection Processed time-domain signal derived from frequency signal.The signal of this generation includes about the movement of people, breathing and cardiomotility Information, and it is referred to as raw sensor signal.In Fig. 2, is indicated to illustrate, indicate system with pulsed continuous wave signal Radio frequency sensor components.In optional embodiment, Orthogonal injection is also can be used in this system, in the Orthogonal injection, is used 90 degree of phase phase difference of two carrier signals.In the case where pulse becomes the time very short limit, this system can characterize again For ultra wide band (UWB) radio frequency sensor.By using the signal-to-noise ratio that continuous wave system also can be improved, wherein being continually transmitted RF signal.

Fig. 3 provides the representative raw sensor letter obtained when sensor is close to body surface (for example, in 5cm) Number.The main component in raw sensor signal received by be ballistocardiogram and sensor and people relative motion. In order to reduce relative motion, elastic restraint mechanism or similar means can be used to be mechanically secured on skin for sensor unit.Figure 3 be the example with the raw sensor signal for accounting for leading ballistocardiogram component (in this case, in the elbow of upper arm It is measured on the inside of portion).This indicates 5 seconds data being collected into using the system of 26GHz pulsed continuous wave prototype.In such feelings Under condition, heartbeat (pulse is associated more than or less than the point of threshold value with wherein signal) will be determined by technology using threshold value.It is more multiple (but being typical case) miscellaneously, more complex but repeatable pulse shape will be presented in ballistocardiogram.Thus, for example by The pulse shape template implemented with filter can be related to the heart signal of acquisition, and the high place of correlation will act as heartbeat Position.Correspondingly, this system is by the wave crest in the handled time-domain signal of discrimination or by receiving signal and prototypical cardiac letter Number relativity of time domain or by other means, identify the heartbeat of living body.This processing generates the hair to distinguish each heartbeat A series of label of times of raw time.It can be marked by processor using these times to issue the sound of each heartbeat of living body Intermittent icon on signal, or point bright display.

Time label when giving each event and occurring, it is possible for calculating heart rate.For the letter being shown in FIG. 3 Number, the point for signal being passed through threshold value is labeled as cardiac event time B by us_n(wherein, n is beating number).Thus we can incite somebody to action It is 1/BB that instantaneous heart rate, which calculates,_n, wherein BB_n=B_n-B_n-1(beating interval).In practice, it may be more useful to define in the time Average heart rate in period (for example, 10 seconds).This can by being counted to the beating number occurred in window at 10 seconds, then remove It is realized with 10 with obtaining average pulsatility number per second.For example, being had occurred in window in the example being shown in FIG. 3 at five seconds 5.9 beatings, so that the heart rate of report is (5.9/5) per minute × 60=71 beating.

When the present apparatus is further away from body (for example, 1 meter or farther), the raw sensor signal received will be complete The combination of body movement, breathing and cardiomotility.The upper curve of Fig. 4 shows the photoelectricity volume pulsation obtained from adult body The time course of wave signal, wherein each heartbeat is associated with different mode (distinctive pattern).Under Fig. 4 Portion's curve indicates the signal obtained simultaneously at several meters of distances from same target, and (separate) that shows separation is exhaled Suction and heart signal.Specifically, circles highlight skin movements associated with each heartbeat.Skin movements typically with pulse Dichroism (dichrotic) wave crest alignment in waveform.

In cases of usage further away from the body, as described above, the original signal received includes to close In breathing and heart rate and the information of all-around exercises.For evaluate and visualize the technology of breathing and heart information be using when M- frenquency representation, as short time discrete Fourier transform and wave crest detect algorithm.Processor may also be configured to using the frequency for receiving signal Domain handles the physiological activity to identify living body.Detailed description is presented below, but widely it includes obtaining with time t₁For in The frequency spectrum in the period of the heart, and find out with desired breathing and heart frequency to deserved best frequency spectrum wave crest.For the period, Two wave crests can be noted that, and be considered as time t₁The heart and respiratory rate at place.Then the new period can be formed, this is new Period and former period are overlapping, but the present new period is with t₂Centered on, and can calculate and be formed in time t₂It the heart at place and exhales Inhale two new frequencies of frequency.Fig. 5 indicate by this technology be applied to 50 second datas as a result, with 20 seconds length of window, With 19 seconds overlap.Over time, can be traced about 20 times per minute breathing under respiratory components and per minute Cardiac component under approximate 70 beatings.

Fig. 6 provides the schematic diagram of the system when multiple radio frequencies (RF) block is used for the transmitting and reception of radio wave.At this In a schematic diagram, there are three independent RF block, each RF block can receive and emit radio wave.Each RF block is similar to first Preceding RF block shown in figure 2.They will generate multiple separate copies of overall signal from detected individual, so as to use Signal processing extracts independent component motion (for example, breathing, heart signal and upper body exercises).Note that day if necessary Line can also be emitted with isolated frequency.The physical separation (for example, by being greater than quarter-wave) of antenna will also make to emit road Diameter is statistically independent.

Fig. 7 indicates the schematic diagram of the display for this system.This system will typically show such as Current heart rate, current The parameters such as respiratory rate and respiratory sinus arrhythmia degree.It can be measured since this system can be easily integrated with The device (for example, using global positioning system-GPS) of position, thus can also on system output device display position.This is System will also have the ability for being displayed for useful trend, in the past one hour heart rate, RSA value of last week etc..And Enter location information further advantages in that, it allows this system to be used in standard tests of fitness.For example, general cardiovascular health Good sign is " mile fitness test ".In this test, people trippingly walks one mile, and records it at one mile End at pulse.Positioning system will automatically notify them in people's miles per hour of having walked, and record at this time Heart rate.Similarly, in clinical application, six minutes walk tests are routinely used.In this walking, it is desirable that people presses them The step of oneself is walked six minutes, and mark of the distance passed by as their general cardiovascular healths.Integrated positioning system System will automatically keep the tracking to distance of passing by and heart rate and respiratory rate during the period.In this way, by including positioning The utilization rate of this system can be improved in system, which is configured to the position of monitoring living body, and at the same time tracking their life Reason activity.

Fig. 8 shows the schematic diagram how this system calculates parameter relevant to ventilation threshold.The present apparatus is recordable in fortune Heart rate and respiratory rate on the dynamic period.At the end of movement, the present apparatus can draw heart rate and be averaged to what is seen under the heart rate Respiratory rate.The schematic illustration of such curve is shown in FIG. 8.If exercise intensity close to the maximum value of people, Curve can be used to distinguish " turning point ", and at " turning point ", respiratory rate quickly increases relative to heart rate.Such case hair Respiratory rate at raw can be used as the substitute of ventilation threshold (VT).It, can be in several weeks or several months when people undergoes fitness program The value of this parameter is tracked in the process.

In one embodiment, this system includes sensor unit and monitoring and display unit, and wherein result can be divided Analyse, visualize and send to user.If desired, sensor unit and display/monitoring unit may be incorporated into single self-contained unit. The apparatus may include one or more motion sensors (for detecting general body kinematics, breathing and heart rate)；Processing capacity (the export signal directly related with cardiomotility, breathing and movement, and therefore export respiratory rate, heart rate and movement etc. Parameter)；Display capabilities (provide visual feedback)；Hearing ability (provides sound feedback, such as its frequency is with the sound of respiratory variations The sound of tune or the heartbeat detected every time)；The data that will acquire are sent to communication capacity (the wired or nothing of the unit of separation Line).The unit of this separation can execute above-mentioned processing, display and hearing ability.

More particularly, typical sensor will include one or more radio frequency Doppler (Doppler) sensors, these Radio frequency Doppler sensor emission RF energy (typically in the range of 100MHz to 100GHz), and connecing using reflection Collection of letters tectonic movement signal.In order to be easy to explain, we, which will first restrict our discussion to, only uses a sensor The case where unit.The principle of the work foundation is to emit following rf wave from the unit

S (t)=u (t) cos (2 π f_ct+θ) (1)

In this example, carrier frequency is fc, and t is the time, and θ is arbitrary phase angle.U (t) is pulse shape.? In continuous wave system, value is always one, and can save from formula (1).In general, pulse will be defined as

Wherein T is periodic width, and T_pIt is pulse width.Wherein T_p< < T, this becomes pulsed continuous wave system.In pole In the case of end, work as T_pTime become very in short-term, the frequency spectrum of the signal of sending becomes very wide, this system be referred to as ultra wide band (UWB) radar or impulse radar.Alternatively, the carrier frequency that RF emits signal can be changed (linear frequency modulation (chirped)), To generate so-called frequency modulation continuous wave (FMCW) system.

The local oscillator being coupled with the circuit for being used to apply pulse gate is used to generate this in sensor systems A radiofrequency signal.In FMCW, voltage-controlled oscillator is used together to generate RF signal with voltage-frequency converter For emitting.The coupling of RF signal and air is realized using antenna.Antenna can be the (more or less in all directions of omnidirectional Equally transmission power) or orientation (preferentially transmission power in a certain direction).It may be advantageous that in such systems Using directional aerial, so that the energy of transmitting and reflection is mainly from a direction.This system and such as simple dipole antenna, Various types of antennas such as paster antenna and helical antenna are mutually compatible with, and the selection of antenna can be by all directions as required The influence of the factors such as property, size, shape or cost.It should be noted that this system can be by having shown that for people using safe Mode operate.This system is proved with < 1mW (0dBm) and lower total system emitted average power.RF is radiated Recommendation safety level be 1mW/cm².At 1 meter of the system that distance is emitted with 0dBm, equivalent power density will be recommended than this The limit is at least 100 times small.

In all cases, the signal of sending will be reflected off object (such as air-body to reflect radio wave Body interface), and some reflection signals will be received back at transmitter.Receiving signal and transmitting signal can be known as being mixed (in the form of analog or digital) is multiplied in the standard electronic device of device.For example, in the cw case, mixed frequency signal will be equal to

M (t)=γ cos (2 π f_ct)cos(2πf_ct+φ(t)) (3)

Wherein φ (t) be transmitting and receive signal path length difference (it is described reflection leading feelings are accounted for by single reflective object Under condition), and γ is the decaying undergone by reflection signal.If reflective object is fixed, φ (t) is fixed, and m (t) it is also fixed.Enable that we are interested to be, just during exercise, m (t) will be changed over time reflective object (for example, chest). As simple example, if chest is undergoing sinusoidal motion due to breathing:

Resp (t)=cos (2 π f_mt) (4)

So mixed frequency signal will include f_mPlace component (and can by filter simply remove centered on 2fc point Amount).Raw sensor signal is referred to as by the signal of low-pass filter output after mixing, and includes about moving, exhale The information of suction and cardiomotility.

The amplitude of raw sensor signal is influenced by the mean path distance of reflection signal, so as to cause in sensor Detection zero and wave crest (sensor less sensitive or more sensitive region).This influence can be minimum by using quadrature technique Change, in the quadrature technique, (two signals will be called I and Q points to the signal of 90 degree of transmitter while transmitter phase difference Amount).This will lead to the two reflection signals that can be first mixed, and eventually lead to two raw sensor signals.In the two signals Information can be combined by obtaining their mould (or other technologies), to provide the raw sensor signal of single output.

In the uwb case, it may be preferred for obtaining the optional method of raw sensor signal.In the uwb case, can lead to Cross measurement transmitting pulse and peak reflected signal between delay determine to most effective air-body interface distance away from From.For example, if pulse width is 1ns, and the distance from sensor to body is 0.05m, then the wave crest in pulse is anti- Total time m (τ) passed through before penetrating will be 0.1/ (3 × 10⁸) s=0.33ns.By emitting a large amount of pulses (for example, 1ns pulse Every 1 μ s) and assume that path distance just slowly changes, we can export raw sensor signal, as on the period Time delay is averaged.

In this way, radio frequency sensor can obtain the movement for the body part that system is directed to.Can be used directional aerial or Multiple RF transmitters realize direction selection.It is shown in the lower curve of Fig. 4 and uses pulsed continuous wave system in this way The aggregate motion for the chest that system obtains (it is mainly breathed and the combination of heart signal).However we emphasize that, continuous wave, Similar signal also can be obtained in FMCW or UWB radar.

Further, since most of reflected energy is received from the superficial layer of skin, so this motion sensor can also obtain To ballistocardiogram, this is the performance of heartbeat at skin surface caused by due to the blood pressure beaten every time.Exist The example of the surface ballistocardiogram obtained by RF motion sensor is shown in Fig. 3.In this case, ballistocardiogram By emphasizing (emphasized) close to the sensor of skin (upper arm), and respiratory components are sightless.

In order to improve the quality of the sensor signal measured, it various method limitations can be used to be collected by sensor from it and reflect The physical size of energy.For example, transmitting antenna " orientation " can be made (that is it emits in a certain direction compared with multipotency Amount), as can the receiver antenna.The technology of referred to as " time domain gating " can be used for only measuring from certain from sensor The reflection signal generated in signal at physical distance.The practical ways for implementing this are to ensure that, receive signal in pre- timing Between Duan Shangyu transmitting signal be mutually mixed.For example, it is envisioned that issuing 12ns pulse at time t=0ns.If reflective object is 150cm is remote, then reflected impulse will be received (the 300cm flower 10ns because light is passed by) first after 10 ns.It is assumed that being not intended to detect The second object 300cm it is remote, the reflected impulse from this second object is just arrived first at until time t=20ns.Therefore, such as Fruit is only allowed in the period from t=10ns to t=15ns in the mixing emitted between reception pulse, then received All information will be only related to the first reflective object.Frequency domain gating can be used for for the movement of reflective object being restricted to a certain frequency it On.

In the simple embodiment of this system, the single antenna with single carrier wave frequency will be used.The antenna is by starting Penetrate the effect with receiving antenna.However, in principle, more piece-root graftings receipts and transmitting antenna can be used, multiple carrier frequencies such as can be used Rate is such.In the case where multiple frequencies (for example, in 500MHz and 5GHz) measure, lower frequency be can be used to accurately really Then fixed big movement can subtract lower frequency (these higher-frequencies without phase ambiguity from upper frequency sensor signal Rate sensor signal is more suitable for measuring small movement, such as heart signal).

All these sensor inputs are all fed in the unit for handling and showing, and for isolated unit The unit (monitoring unit) that may emit.

Then sensor input is combined by system using its processing capacity, to provide many useful outputs, and with Significant mode shows these outputs.These steps execute as follows.

Cardiorespiratory monitor major design is used to provide the information about heart rate and breathing.When the person is moving, sensor Signal will often be dominated by motion, and in this case, need to handle to reduce motion artefact problems.For in the feelings for having noise Breathing is calculated under condition and the optimization technique of heart beat activity is as follows.

Obtain the original signal in the period (for example, 20 seconds) of desired length.Use the skills such as smooth figure average period The frequency spectrum of art estimation this period of signal.Generally, due to typically (about with from 10 to 25 breathings frequency per minute Breathing 0.15-0.45Hz) is generated, and cardiomotility occurs in the range of 60-120 beats per minute clock (1 to 2Hz), institute To have in the range of 0.15-0.45Hz and 1 to 2Hz with the frequency spectrum of signal there are two wave crest.For the period, these wave crests The frequency of point can be referred to as respiratory rate and heart rate.The result of the spectrum analysis in each period can be arranged temporally Column, to form T/F respiratory curve figure, which is the useful means of visualization entire breathing and cardiomotility.Note Meaning, these periods can overlap, so as to calculate the respiratory rate located at any time and heart frequency (for example, Fig. 5 is shown point The case where analysis period is one second interval).

The presence of big motion artifact may obscure above-mentioned processing, so in certain circumstances, it may be necessary to pre-processing letter Number to reduce the influence of motion artifact.Due to moving the big numerical signal caused in the time domain of processing, configurable processor greatly For measuring the energy content of filtering signal, so that identifying the body of living body and energy content compares with predetermined power value The period of body movement.Method for carrying out this is with the linear high pass filter pre-filtering period (to remove for example 0.05Hz all frequencies below).Optional way will be the length of window by 10 seconds to data progress median filtering, and from Original signal removes median filtering signal.Optionally, when we can identify these movements by the high energy content of movement slot Section.These movement slots may cause the pseudomorphism in processed signal, so removing measurement period appropriate can be used Spectrum analysis.Specifically, when calculating the spectrum of the epoch, the data in these high motion parts do not include in the estimation (using the technology of referred to as Lip river nurse (Lomb) cyclic graph, which provides spectrum estimation from the data for losing section).

It is to obtain multiple signals from multiple sensors for improving the optional processing technique of the precision of heart rate and breathing detection. This is in the case where high motion artifact, as being used in treadmill environment and feelings that people jogs in sensors field region when this system Condition is particularly advantageous.In such a situation it is preferred to solution be there are multiple sensors (for example, m, wherein m can With typically in the range of four to 16, but any number can also be changed to from one).In practice (for reasons of cost), It perhaps is efficiently only single transmitting antenna, He Duogen receiving antenna, rather than every antenna not only emits but also receives.Equally, It may be beneficial that making the RF signal of one or more antenna generation at multiple frequencies.However, the embodiment of this method is to make With a transmitter, and m signal is received in the sensor (each distance will undergo different phase delay and amplitude change Change).Another useful embodiment of system is the multiple sensors operated at different frequencies, wherein relatively low frequency is used for Estimate the big body kinematics of living body, and relatively high frequency is used to estimate the smaller movement of living body.For example, grasping at 1 GHz The sensor of work is sensing that is useful, and operating at 100GHz in the same system for the movement in detection cm range Device can help to the movement of detection millimeter.

It is signal vector x that useful model, which is by m reception signal collection:

It can reasonably assume that, each signal indicates the mixing from multiple sources (for example, one comes from from breathing, one Cardiomotility, one from left arm movement etc.).Therefore, receiving signal indicates the linear mixture of source w, so that

W=Ax is wherein

In practice, we are interested in obtaining signal w, because they will cleanly separate interested different components. Our key factor is helped in this analysis is, multiple source signals are independent (that is, for example, heart signal is independently of exhaling It inhales, the breathing is independently of arm motion).Under this assumption, the algorithm that x maps back w will be received there are many, and these are claimed Make independent component analysis (ICA) technology.Especially, we can be advanced optimized by applying certain constraint conditions to source signal Our solution (for example, it should have basic frequency in the range of 0.15 to 0.25Hz).Such algorithm is known as Constrain ICA algorithm.Useful technical investigation and analytical evaluation in ICA analysis can be in " Independent component analysis for Biomedical signals (independent component analysis for biomedicine signals), " C.J.James and C.W.Hesse, It is found in Physiological Measurement v0l.26 (1), R15-R39, Feb 2005.

In addition to determining respiratory rate and amplitude, heart rate and movement, this system provides the device of combination signal, to count Calculate other useful output.For example, the useful mark of overall cardiorespiratory health is respiratory sinus arrhythmia (RSA).This measurement The influence to heart rate is breathed, and coupling is stronger, overall cardiorespiratory health is better.Generally, there is configuration processor to use measurement Heart rate and respiratory rate information calculate the function of the parameter of respiratory sinus arrhythmia.A kind of means may be to use The cross-spectral analysis of the heart rate of measurement and respiratory rate signal calculates the parameter of respiratory sinus arrhythmia.

However, in the presence of the various technologies for calculating RSA.One embodiment of the system is as follows.

It obtains measurement period (for example, 60 seconds), the activity of people is fairly constant on the measurement period.It obtains in heart signal (coherence is typically defined to be: the cross-spectral density of two signals obtains coherence between breath signal divided by separation Each signal power spectral density the obtained ratio of square root).Phase in determining frequency band (for example, 0.15-0.25Hz) The peak of stemness is taken as the measurement of the coupling between heart rate and breathing.When this coherence value may span across different movements Phase is tracked, or compared with mean of population.

Another useful measurement of the cardiorespiratory performance obtained by this system is, only by heart rate measurement or by heart rate and breathing speed Ventilation threshold is estimated in the combination of rate.This system, which can be configured by, to be made the heart rate measured and is measured in determining measurement period Respiratory rate be associated to calculate the useful parameter (such as ventilation threshold) of cardiorespiratory performance.For from combined heart rate and breathing The preferred embodiment that rate obtains ventilation threshold is the curve for checking per respiratory cycle heartbeat relative to respiratory rate.At this In curve, there is characteristic kink, this feature turning point occurs at frequency corresponding with ventilation threshold.

Finally, this system provides the device for useful information to be sent to its user.Display device can be such as hand The form of table has the parameters such as Current heart rate, current breathing rate and position.User may also have viewing trend The ability of screen (trend screen), the trend screen show on different time scale (time scale) with front center The chart of the derived parameters such as rate, former respiratory rate and the RSA coherence that estimates.In some usage scenarios, beneficial , design may include the shell of one or more sensors, processor and display.The shell is suitably adapted for being held in use With convenient to use in the hand at family.Shell also may be incorporated into other functionality, if telecommunication or positioning system are (for example, cellular phone Mobile phone by be this shell specific embodiment).

The narration of industrial applicibility

Movement, breathing and heart rate of the present invention monitoring living body such as people in a manner of facilitating with low cost, such as Medicine, safety and sports fitness fields have application.This monitoring is for example in the health of people and commenting for movable cardiopulmonary mark It is useful in fixed.

Claims

1. a kind of system of breathing or cardiomotility for measuring and analyzing living body, the system comprises:

Transmitter is configured to emit radiofrequency signal to living body；

One or more sensors are configured to receive the radiofrequency signal reflected from living body；

The radiofrequency signal reflected from living body is mutually mixed, to generate by frequency mixer with a part of the radiofrequency signal emitted to living body Mixed frequency signal；

Processor is configured to determine the measurement result of breathing or cardiomotility partially by following operation:

Measure the energy content of the raw sensor signal derived from the mixed frequency signal；

Pass through the period by the energy content of measurement compared with predetermined power value relatively to identify body kinematics；

The frequency spectrum in the period of raw sensor signal is calculated, wherein excluding the raw sensor letter from the calculating of the frequency spectrum Number one or more sections corresponding with the period of the body kinematics identified；And

Find out the frequency spectrum wave crest corresponding with desired respiratory rate or desired heart frequency in the frequency spectrum；And

Display is arranged to the letter that selection relevant to the identified measurement result of breathing or cardiomotility is shown to user Breath.

2. system according to claim 1, the range of the desired respiratory rate be from 0.15Hz to 0.45Hz, and Wherein the range of the desired heart frequency is from 1Hz to 2Hz.

3. system according to claim 1, wherein the frequency spectrum is Fu in short-term in the period of the raw sensor signal Vertical leaf transformation.

4. system according to claim 1, wherein one or more of sensors include by the more of different frequency work A sensor.

5. system according to claim 1, wherein the radiofrequency signal to living body transmitting is continuous wave signal.

6. system according to claim 5, wherein the continuous wave signal is frequency modulation continuous wave signal.

7. system according to claim 6, wherein generated using voltage-controlled oscillator and voltage-frequency converter by The radiofrequency signal of transmitter transmitting.

8. system according to claim 1, wherein the transmitting mean power of the radiofrequency signal emitted is less than 1mW.

9. system according to claim 1, wherein the radiofrequency signal to living body transmitting is pulsed continuous wave signal.

10. system according to claim 1, wherein the radiofrequency signal emitted to living body includes two of 90 degree of phase phase difference Carrier signal.

11. system according to claim 1, wherein the radiofrequency signal emitted includes the arteries and veins of the pulse with short pulse width Signal is rushed, the short pulse width generates ultra-wide radar system.

12. system according to claim 1, wherein cardiomotility is retouched from the surface heart impact for deriving from the mixed frequency signal Note figure obtains.

13. system according to claim 1 a, wherein sensor in one or more of sensors is configured to Exclude the radiofrequency signal from the object reflection being located at the sensor at the position for being apart more than specific physical distance.

14. system according to claim 1, wherein the transmitter is coupled to directional aerial.

15. system according to claim 1, wherein the system also includes sound feedbacks.

16. system according to claim 15, wherein the sound feedback includes tone or pass of the frequency with respiratory variations In the sound of the heartbeat detected every time.

17. system according to claim 1, further includes:

Linear high pass filter, it is described to remove that the linear high pass filter carries out pre-filtering to the raw sensor signal One or more parts corresponding with the period of body kinematics of raw sensor signal.

18. system according to claim 1, wherein the processor is configured to the raw sensor signal application Median filter, and frequency spectrum is calculated according to the raw sensor signal after the median filtering from the median filter.

19. system according to claim 1, wherein the processor is further configured to based on cardiomotility and respiratory activity The measurement result of determination calculate (a) respiratory sinus arrhythmia, or based on (1) cardiomotility or (2) respiratory activity and The measurement result of the determination of cardiomotility calculates (b) ventilation threshold.

20. system according to claim 19, wherein the processor is configured to determine the survey of breathing and cardiomotility Amount is as a result, and wherein the processor is configured to the measurement result calculating respiratory Dou Xingxin based on breathing and cardiomotility Restrain not normal or ventilation threshold.

21. system according to claim 20, wherein the processor is configured to partially by being breathed and the heart Coherence between dirty movable measurement result calculates respiratory sinus arrhythmia.

22. system according to claim 20, wherein the processor was configured to partially by identification every breathing week Phase heartbeat calculates ventilation threshold relative to the turning point in the curve of respiratory rate.

23. system according to claim 1, wherein the display is arranged to together with the current of breathing or cardiomotility Determining measurement result display together the one or more charts for the measurement result of breathing or cardiomotility being previously determined.

24. system according to claim 1, wherein the processor is configured to partially by following operation at one section Multiple measurement results of breathing or the cardiomotility of living body are determined in time:

The multiple frequency spectrums for calculating overlapping multiple periods of raw sensor signal, wherein being arranged from the calculating of the multiple frequency spectrum Except one or more sections corresponding with the period of the body kinematics identified of the raw sensor signal；And

Find out the frequency spectrum corresponding with desired respiratory rate or desired heart frequency in each of multiple frequency spectrums of calculating Wave crest.

25. system according to claim 24 is shown and the breathing of living body wherein the display is arranged to user Or cardiomotility in described a period of time determined by the relevant tendency information of multiple measurement results.

26. a kind of method of breathing or cardiomotility for measuring and analyzing living body, which comprises

Emit radiofrequency signal to living body；

Receive the radiofrequency signal reflected from living body；

Transmitting is mutually mixed with the radiofrequency signal of reflection, to generate mixed frequency signal, and is based on the mixed frequency signal,

The measurement result of breathing or cardiomotility is determined partially by following operation:

The frequency spectrum wave crest corresponding with desired respiratory rate or desired heart frequency in the frequency spectrum is found out, and

The information of selection relevant to the identified measurement result of breathing or cardiomotility is shown to user.

27. according to the method for claim 26, wherein the range of the desired respiratory rate be from 0.15Hz to 0.45Hz, and wherein the range of the desired heart frequency is from 1Hz to 2Hz.

28. according to the method for claim 26, wherein the frequency spectrum be the period of the raw sensor signal in short-term Fourier transform.

29. according to the method for claim 26, wherein anti-from living body with being received by multiple sensors of different frequency work The radiofrequency signal penetrated.

30. according to the method for claim 26, wherein the radiofrequency signal to living body transmitting is continuous wave signal.

31. according to the method for claim 30, wherein the radiofrequency signal to living body transmitting is frequency modulation continuous wave signal.

32. according to the method for claim 31, wherein being generated using voltage-controlled oscillator and voltage-frequency converter The radiofrequency signal to be emitted.

33. according to the method for claim 26, wherein the transmitting mean power of the radiofrequency signal emitted is less than 1mW.

34. according to the method for claim 26, wherein the radiofrequency signal to living body transmitting is pulsed continuous wave signal.

35. according to the method for claim 26, wherein the radiofrequency signal emitted to living body includes the two of 90 degree of phase phase difference A carrier signal.

36. according to the method for claim 26, wherein the radiofrequency signal emitted includes the pulse with short pulse width Pulse signal, the short pulse width generate ultra-wide radar system.

37. according to the method for claim 26, wherein cardiomotility is impacted from the surface heart for deriving from the mixed frequency signal What graphy figure obtained.

38. according to the method for claim 26, wherein receiving the radiofrequency signal reflected from living body further include:

Exclude the signal from the object reflection being located at sensor at the position for being apart more than specific physical distance.

39. according to the method for claim 26, further includes:

Carry out sound feedback.

40. according to the method for claim 39, wherein the sound feedback include frequency with the tone of respiratory variations or with The associated sound of the heartbeat detected.

41. according to the method for claim 26, further includes:

Pre-filtering is carried out to remove the raw sensor signal to the raw sensor signal using linear high pass filter Part corresponding with big body kinematics.

42. according to the method for claim 26, wherein to the raw sensor signal application median filter, and according to Raw sensor signal after median filtering from the median filter calculates frequency spectrum.

43. according to the method for claim 26, further includes:

(a) respiratory sinus arrhythmia is calculated based on the measurement result of cardiomotility and the determination of respiratory activity, or is based on (1) measurement result of cardiomotility or (2) cardiomotility and the determination of respiratory activity calculates (b) ventilation threshold.

44. according to the method for claim 43, wherein determining the measurement result of breathing and cardiomotility, and being wherein based on The measurement result of breathing and cardiomotility calculates respiratory sinus arrhythmia or ventilation threshold.

45. according to the method for claim 44, part ofly by obtain breathe with the measurement result of cardiomotility it Between coherence calculate respiratory sinus arrhythmia.

46. according to the method for claim 44, part ofly by identifying per respiratory cycle heartbeat relative to breathing speed Turning point in the curve of rate calculates ventilation threshold.

47. according to the method for claim 26, further includes:

Together with the currently determining measurement result of breathing or cardiomotility to user show breathing or cardiomotility before One or more charts of determining measurement result.

48. according to the method for claim 26, determining living body in a period of time by following operation part ofly Multiple measurement results of breathing or cardiomotility:

49. according to the method for claim 48, further includes:

To user show breathing with living body or cardiomotility in described a period of time determined by multiple measurement result phases The tendency information of pass.